Bears, ravens adjust to new rules at water treatment plant

March 26, 2013

Mammoth Community Water District plant maintenance supervisor Rob Motley had to get creative in keeping bears and ravens out of the wastewater treatment plant.

The Mammoth Community Water District Wastewater Treatment Plant is located on the edge of Jeffery pine forest and sagebrush scrub, a setting that provides the numerous wildlife in the area a banquet of alluring smells and a steady supply of fats and grease in the wastewater tanks. It is thus a it a popular spot for local animals, particularly bears and ravens.

These conditions present a unique and consistent challenge for district employee Rob Motley, plant maintenance and instrumentation supervisor at the district.

â€śBears are basically 500-pound raccoons with powerful and dexterous hands bent on destruction driven by appetite,â€ť explains Rob. For example, one winter morning, staff arrived to discover a bear had removed a heavy metal grate and tossed it into another tank where it broke expensive machinery. District staff was forced to drain the tank to perform repair and the bearâ€™s quest for an easy meal had a toll of 36 hours of district staff time plus the expense of replacing the broken equipment.

In addition to the bears, ravens have been an ongoing problem at the wastewater treatment plant. Motley observes, â€śI have seen over fifty at the plant at once.â€ť The ravens land in the wastewater tanks to scrounge for food and then take off to roost nearby; making a mess anywhere they go afterwards.

The bottom line is Motley and his staff have had a constant maintenance battle to keep the plant grounds sanitary.

It was time to make some changes.

After continuous innovation and testing, Motley has successfully implemented measures to keep bears and ravens from bathing and dining in the wastewater tanks. The district has installed an electric fence around the perimeter of the wastewater tanks. This new fence has proven to be an effective, non-harmful method of keeping the bears out; they can sense the electricity and wonâ€™t even touch the fence.

Now that the bears are kept out, netting has been placed over the wastewater tanks to keep the ravens from dining and dashing. The success of the netting and deterrence of bears has convinced the district to invest in sturdy wire mesh covers for the open tanks. The results of district staff time and financial investments to maintain a critter-free wastewater plant has increased the plantâ€™s efficiency and decreased employee time repairing damage and cleaning up after our wild neighbors.